Moving freight by highway trucks has been increasing in volume for several years, and it appears that it will continue to increase in the future. This method of freight handling has proved to be more efficient and quicker than any other means in a large majority of situations. Nevertheless, this method has need of further improvement. A large problem is the energy needed to overcome wind resistance. It has been recognized that by streamlining vehicles they can accomplish great savings in fuel expenses and can travel faster. A recent attempt to help solve this problem is the use of a wind deflector attached to the top of the cab of the tractor which provides some streamlining of air flow from the cab to the broad flat or rounded front surface of the semitrailer. Usually, the top of the cab is lower than the top of the semitrailer and this makes the front of the semitrailer react almost like a sail catching the full force of the wind. Eddy currents form behind the cab and behind the semitrailer, and such currents are known to provide great wind resistance to the truck. Furthermore, such eddy currents are produced underneath the truck and its trailers which add to the wind resistance. There is a great need to provide a maximum streamlining effect in order to speed up freight shipments and to reduce shipping costs.
It is an object of this invention to provide an improved streamlined highway truck. It is another object to provide a streamlined highway truck which incorporates a tractor, a semitrailer, and, if desired, a second trailer. Still other objects will become apparent from the more detailed description which follows.